Automatic detection of a cable trap

ABSTRACT

Firmware is installed in a cable modem, enabling detection of the presence or absence of a cable trap in the feed of a customer location. Such a cable modem includes a trap-detection module and a trap-detection object. The trap-detection module is configured to determine whether a video signal is present at a cable-television frequency. The trap-detection object is configured to store data as to whether the video signal is present. For example, a first piece of data is stored if the video signal is present, indicating absence of a properly functioning cable trap between a cable head-end and the cable modem. A second piece of data is stored if the video signal is absent, indicating presence of a properly functioning cable trap between the cable head-end and the cable modem.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is generally directed to cable television. Moreparticularly, the present invention is directed to transmission anddetection of video, voice, and data signals over a cable-televisionnetwork.

2. Background Art

A cable modem is typically configured to concurrently receive severaldifferent types of signals over a single coaxial cable. For example, acable modem may concurrently receive television signals, voice signals,and data signals. To enable a customer to concurrently access theinformation provided by the different signals, a customer systemtypically includes software and/or firmware modules specially designedto process the different signals. For example, a customer system mayinclude one or more modules to process Internet protocol-based(IP-based) television signals, one or more modules to process voicesignals, and one or more modules to process data signals. Alternatively,the cable modem may pass video-based television signals directly to aset-top box. In either case, a customer can typically watch television,talk on the telephone, and surf the Internet—all at the same time.

To prevent a customer from accessing cable-services content (e.g.,premium channels) without proper authorization, cable-service providershave historically used cable traps. A cable trap is a type of filter.Specifically, cable traps are configured to block the transmission ofone or more cable channels (e.g., frequencies). If a cable trap isproperly installed at a location (e.g., a tap) between a cable head-endand a cable modem at the customer location, the delivery of one or morechannels into the customer's cable modem is blocked, thereby preventingthe customer from receiving services for which he has not paid. Althoughmodern cable systems now often use digital set-top box technologies tocontrol the delivery of service to customers, cable traps continue to beused for customers who subscribe to only basic cable or cable-modemservices in order to block extended basic services.

Unfortunately, cable traps are a physical-security mechanism and, assuch, are less secure than digital set-top box technologies. Inparticular, cable traps are subject to alteration, especially removal,in order to enable reception of unauthorized services. Due to thissusceptibility, a typical cable company regularly audits its facilitiesto ensure that cable traps remain in place where they belong.

However, conventional cable-trap audits are problematic for severalreasons. As an initial matter, these audits typically involve manualinspection—an expensive and time-consuming process. Moreover, theseaudits can be ineffective in certain situations (e.g., when advancednotice is required before inspection). Such situations may arise, forexample, in the context of multi-dwelling unit (MDU) buildings. In MDUbuildings, cable traps are usually located in a utility closet. Often,advanced notice must be given to the building's superintendent beforeaccessing the utility closet. However, even if a cable trap had beenremoved and/or tampered with, the advanced notice provides theopportunity for the cable trap to be re-installed and/or replaced beforethe inspection occurs.

Given the foregoing, what is needed is automatic detection of cabletraps and applications thereof.

BRIEF SUMMARY OF EMBODIMENTS OF THE INVENTION

The present invention meets the above-described needs by providing forautomatic detection of cable traps and applications thereof.

For example, an embodiment of the present invention provides acomputer-implemented method for automatic cable trap-presencevalidation. This method includes several steps. In a first step, atrap-detection object is created in a management information base of acable modem. The trap-detection object is configured to maintain datacorresponding to whether a properly functioning cable trap is presentbetween a cable head-end and the cable modem. In a second step, the datafrom the trap-detection object is obtained to determine whether theproperly functioning cable trap is present between the cable head-endand the cable modem.

Another embodiment provides a method, implemented in a cable modem, forautomatic trap-presence validation. This method includes several steps.In a first step, it is determined whether a video signal is present at acable-television frequency. In a second step, data as to whether thevideo signal is present is stored. For example, a first piece of data isstored if the video signal is present, indicating absence of a properlyfunctioning cable trap between a cable head-end and the cable modem. Incontrast, a second piece of data is stored if the video signal isabsent, indicating presence of the properly functioning cable trapbetween the cable head-end and the cable modem.

A further embodiment provides a cable modem for automatic trap-presencevalidation. The cable modem includes a trap-detection module and atrap-detection object. The trap-detection module is configured todetermine whether a video signal is present at a cable-televisionfrequency. The trap-detection object is configured to store data as towhether the video signal is present. For example, a first piece of datais stored if the video signal is present, indicating absence of aproperly functioning cable trap between a cable head-end and the cablemodem. In contrast, a second piece of data is stored if the video signalis absent, indicating presence of the properly functioning cable trapbetween the cable head-end and the cable modem.

A still further embodiment of the present invention provides a tangiblecomputer-readable medium having stored thereon computer-executableinstructions that, if executed by a computing device, cause thecomputing device to perform a method for automatic trap-presencevalidation. The method includes several steps. In a first step, it isdetermined whether a video signal is present at a cable-televisionfrequency. In a second step, data as to whether the video signal ispresent is stored. For example, a first piece of data is stored if thevideo signal is present, indicating absence of a properly functioningcable trap between a cable head-end and the cable modem. In contrast, asecond piece of data is stored if the video signal is absent, indicatingpresence of the properly functioning cable trap between the cablehead-end and the cable modem.

Further features and advantages of the invention, as well as thestructure and operation of various embodiments of the invention, aredescribed in detail below with reference to the accompanying drawings.It is noted that the invention is not limited to the specificembodiments described herein. Such embodiments are presented herein forillustrative purposes only. Additional embodiments will be apparent topersons skilled in the relevant art(s) based on the teachings containedherein.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

The accompanying drawings, which are incorporated herein and form partof the specification, illustrate the present invention and, togetherwith the description, further serve to explain the principles of theinvention and to enable a person skilled in the relevant art(s) to makeand use the invention.

FIG. 1 illustrates an example system in accordance with an embodiment ofthe present invention.

FIG. 2 is a block diagram of example components included on a user end.

FIG. 3 illustrates an allocation of an available spectrum as used forcable-television services, voice services, and data services.

FIG. 4 is a block diagram of example hardware components of a cablemodem in accordance with embodiments of the present invention.

FIG. 5 is a block diagram of example software components of a cablemodem in accordance with an embodiment of the present invention.

FIG. 6 is a block diagram of an example method for trap-presencevalidation in accordance with an embodiment of the present invention.

The features and advantages of the present invention will become moreapparent from the detailed description set forth below when taken inconjunction with the drawings, in which like reference charactersidentify corresponding elements throughout. In the drawings, likereference numbers generally indicate identical, functionally similar,and/or structurally similar elements. The drawing in which an elementfirst appears is indicated by the leftmost digit(s) in the correspondingreference number.

DETAILED DESCRIPTION I. Overview

The present invention is directed to automatic detection of cable trapsand applications thereof. Throughout this document, references to “oneembodiment,” “an embodiment,” “an example embodiment,” etc., indicatethat the embodiment described may include a particular feature,structure, or characteristic, but every embodiment may not necessarilyinclude the particular feature, structure, or characteristic. Moreover,such phrases are not necessarily referring to the same embodiment.Further, when a particular feature, structure, or characteristic isdescribed in connection with an embodiment, it is submitted that it iswithin the knowledge of one skilled in the art to affect such feature,structure, or characteristic in connection with other embodimentswhether or not explicitly described.

In an embodiment, software (firmware) is installed on a cable modem,enabling it to detect and report the presence or absence of a cable trapin the feed to a customer location. Accordingly, embodiments of thepresent invention may enable a cable-services provider to determinewhether cable traps are properly installed between a cable head-end anda customer location without an expensive, time-consuming, andpotentially ineffectual manual inspection. Additionally oralternatively, embodiments of the present invention may enable acable-services provider to identify one or more specific customerlocations for manual inspection, rather than manually inspecting allcustomer locations within a geographic area.

A standard cable modem is capable of detecting digital video signals andenergy associated with the carrier of the digital video signals. Forexample, a standard cable modem can detect thequadrature-amplitude-modulation (QAM) digital carriers typically usedfor digital video. A standard cable modem can also typically detect thepresence of energy associated with NTSC or PAL video.

Embodiments of the present invention leverage one or more of thesecapabilities to detect and report the presence or absence of a cabletrap based on the respective absence or presence of a signal on one ormore channels within a trapped band. More specifically, the absence of aQAM digital carrier signal presumptively confirms the presence of acable trap. In contrast, the presence of a QAM digital carrier signalpresumptively confirms the absence of a cable trap.

To detect the presence or absence of QAM digital carriers an embodimentof the present invention provides a trap-detection module. Thetrap-detection module is configured to cause a cable modem to listen toinformation on cable-television frequencies (e.g., channels), enablingthe trap-detection module to detect whether QAM digital signals arepresent at a particular frequency or set of frequencies. As set forthabove, detection of such signals corresponds to the absence of a cabletrap and vice versa. The trap-detection module can then report thisinformation to a cable head-end via a network protocol (such as, forexample, a Simple Network Management Protocol (SNMP)).

Unfortunately, listening to cable-television frequencies (e.g.,channels) potentially disrupts the reception of telephone and datasignals, thereby potentially disrupting a customer's telephone calls andaccess to the Internet. Accordingly, in embodiments the trap-detectionmodule performs steps to mitigate the potential interruptions to voiceand data services. For example, in an embodiment the trap-detectionmodule waits until an attached phone is on the hook (e.g., no call is inprogress) before entering a trap-detection process. Similarly, inanother embodiment the trap-detection module waits until after acable-modem ranging process has completed before entering atrap-detection process, so that the trap-detection process can becompleted without knocking the cable modem offline (which would requireit to re-register). In a further embodiment, the trap-detection moduleidentifies whether an active data connection is in progress and waitsuntil the activity subsides before entering a trap-detection process. Ina still further embodiment, if a trap-detection process is already inprogress, the trap-detection module stalls this process if an attachedphone goes off hook or if a new data connection is initiated, therebyre-establishing fall voice and data connectivity.

During the trap-detection process, the trap-detection module causes thecable modem to tune to one or more specified cable-televisionfrequencies (e.g., channels) and attempts to detect power and/or obtainQAM lock. In an embodiment, if QAM lock is obtained, the trap-detectionmodule attempts to verify the presence of specific data on the channel(such as, for example, a target packet identification (PID)) to confirmthat the signal originates from the cable head-end.

The results of the trap-detection process are stored in local memory(such as, for example, in Management Information Base (MIB) variables)to support subsequent polling from the cable head-end. To poll theresults, the cable head-end may, for example, make use of a SNMP trap.As is well known by persons skilled in the relevant art(s), SNMP trapsare substantially different than cable traps. A SNMP trap is used totransfer information via SNMP. In contrast, a cable trap is a type offilter.

The trap-detection module may be instructed by the cable head-end toenter the trap-detection process in order to poll a specific modem ormodems. Alternatively, the trap-detection module may be preprogrammed toautomatically enter the trap-detection process at regularly scheduledintervals to produce an exception report, identifying locations thatappear to be engaged in receiving unauthorized services.

As set forth above, the trap-detection module may detect the presence orabsence of traps. Detecting the presence of a trap might indicateunauthorized reception of service in, for example, a set-top box that isimproperly moved from one location to another.

Responses to identified exceptions may be included in a manual auditand/or direct-customer communication/follow up. Also, service to aparticular customer location may be disabled. In addition, automaticallyidentified exception cases could be used to automatically targetindirect messaging (e.g., web page redirects, targeted advertisementinsertion within web pages, targeted television advertisements onset-top boxes, and the like). The content of the indirect messaging may,for example, encourage a customer to (legally) upgrade her service.

Before describing additional details of trap-detection modules andprocesses of embodiments of the present invention, it is helpful todescribe an example system in which these modules and processes may beimplemented.

II. An Example System

FIG. 1 is a block diagram of an example cable-services system, which maybe used to automatically determine whether a cable trap is properlyinstalled (e.g., present and working properly) in accordance with anembodiment of the present invention. Referring to FIG. 1, this systemincludes a cable head-end 110, which is coupled to a plurality ofcustomers 120A-C. Cable head-end 110 is also coupled to the Internet 102and cable networks, enabling cable head-end 110 to provide cableservices (e.g., voice, data, and television services) to customers 120.

Taps 124A-C are located between cable head-end 110 and customers 120A-C,respectively. Taps 124 may be located, for example, on a telephone polloutside a single-family residence or in a utility closet of a MDUbuilding. Taps 124 are used to allow a cable-services provider tomonitor a cable signal as it travels from cable head-end 110 tocustomers 120. Coupled between each tap 124 and each customer 120 is acable trap 128. Each cable trap 128 is configured to control thecable-television service provided to customers 120. For example, eachcable trap 128 may be configured to provide a filtering function for(e.g., block) certain channels. In this way, cable traps 128 enable acable-services provider to prevent customers 120 from receiving cableservice for which they have not paid, but only if cable traps 128 areproperly installed (e.g., present and working according tospecifications).

Unfortunately, cable traps 128 may be altered, destroyed, and/orremoved, causing them to fail to properly control the cable-servicescontent provided to customers 120. In conventional methods, acable-services provider manually inspects taps 124 to determine whethercable traps 128 are functioning properly.

In accordance with an embodiment of the present invention, a cable modemat each customer 120 includes a trap-detection module that enables thecable-services provider to remotely determine from cable head-end 110whether cable traps 128 are properly installed, which may eliminate theneed for a manual inspection or may identify specific cable traps 128for manual inspection. To describe how the trap-detection modulefunctions in this manner, it is first helpful to describe examplecomponents that may be included at the location of one or more customers120.

III. Example User-End Components

FIG. 2 is a block diagram, illustrating example components at thelocation of customer 120. These components include a cable modem 210, acomputer 212, a wireless router 216, a computing device 218, a telephone214, a set-top box 220, and a television 222. Cable modem 210 receives afeed from cable head-end 110. Although the feed from cable head-end 110may include data signals, voice signals, and television signals, cablemodem 210 typically receives this feed through a single coaxial cable.Cable modem 210 may receive these signals over a single coaxial cablebecause these signals are allocated to different frequency bands.

For example, FIG. 3 illustrates a spectrum of frequencies typically usedin cable-services networks. The spectrum of frequencies may range fromapproximately 5 megahertz (MHz) to approximately 1,000 MHz. Asillustrated in FIG. 3, this spectrum is broken up into two differentfrequency ranges—a first frequency range 302 and a second frequencyrange 304. Television signals are allocated to second frequency range304, wherein each television signal is allocated to a differentfrequency band (e.g., a different 6-MHz channel) within second frequencyrange 304. Like the television signals, downstream telephone and datasignals—i.e., information flowing from the Internet 102 to customer 120via cable head-end 110—are also allocated to respective frequency bands(e.g., 6-MHz channels) within the second frequency range 304. Upstreamtelephone and data signals—i.e., information flowing from customer 120to the Internet 102 via cable head-end 110—are typically allocated torespective frequency bands (e.g., 1.6-MHz channels, 3.2-MHz channels, or6.4-MHz channels) within the first frequency range 302. Both voice anddata signals are included in packets, using different types ofpacket-switching technology. In particular, voice signals aretransmitted and received using voice-over-Internet protocol (VoIP)technology, and data signals are transmitted and received using standardInternet protocol technology.

As illustrated in FIG. 2, video signals may be provided directly toset-top box 220, which processes the video signals and provides them totelevision 222. Cable modem 210 is configured to provide IP-basedsignals (e.g., IP-based television signals, voice data, and Internetdata) to the different components at the location of customer 120. Forexample, cable modem 210 provides: (i) IP-based television signals totelevision 222 directly or via set-top box 220; (ii) voice data totelephone 214; and (iii) Internet data to computer 212 and computingdevice 218 via wireless router 216.

In the embodiment of FIG. 2, cable modem 210 is illustrated as providingthe respective signals directly to the various other components. This isfor illustrative purposes only, and not limitation. In otherembodiments, cable modem 210 may provide one or more signals to asecondary component before being received by the various othercomponents illustrated in FIG. 2. For example, cable modem 210 maysimply forward video-based television signals to set-top box 220, whichmay process these signals before providing them to television 222.Alternatively, cable modem 210 may process IP-based television signalsand provide them directly to television 222, thereby bypassing set-topbox 220. As another example, cable modem 210 may provide voice data to atelephone adaptor, which may further process these data before providingthem to telephone 214.

Furthermore, cable modem 210 is illustrated as external to computer 212and set-top box 220. This is also for illustrative purposes only, andnot limitation. In embodiments, cable modem 210 may be included in othercomponents included at the location of customer 120. For example cablemodem 210 may be included in a computer (such as, computer 212) and/or aset-top box (such as, set-top box 220).

IV. Example Cable Modem

To receive and process the plurality of signals provided by cablehead-end 110, cable modem 210 includes a plurality of hardware andsoftware (firmware) components. Example hardware components and examplesoftware components of cable modem 210 are described below.

A. Example Hardware Components

FIG. 4 is a block diagram of example hardware components of cable modem210. In the embodiment of FIG. 4, cable modem 210 includes a tuner 402,a receive demodulator 404, a media access control (MAC) device 406, atransmit modulator 408, a central-processing unit (CPU) 410, a memory412, a network interface 414, and a telephone adaptor 416. Each of thesecomponents is described below.

A splitter 401, external to cable modem 210, may split the receivedsignals into EP-based signals (e.g., voice, data, and IP-basedtelevision) and video-based television signals. The IP-based signals areprovided to tuner 402 and are further processed by cable modem 210, asdescribed in more detail below. The video-based television signals areprovided to a set-top box (e.g., set-top box 220) for further processingbefore being sent to a television for viewing.

Tuner 402 tunes cable modem 210 to different frequency bands providedfrom cable head-end 110. For example, tuner 402 may include a diplexerto allow it to use one range of frequencies (e.g., approximately 5 MHzto approximately 42 MHz) for upstream traffic and another range offrequencies (e.g., approximately 42 MHz to approximately 850 MHz) fordownstream traffic. Tuner 402 passes signals to receive demodulator 404.

Receive demodulator 404 demodulates radio-frequency signals providedfrom cable head-end 110 into digital computer-network data. For example,the received radio-frequency signals may be encoded using QAM, which isbased on variations of both the amplitude and phase of a radio-frequencysignal. In this example, receive demodulator 404 converts these QAMsignals into simple signals for conversion into digital binary by ananalog-to-digital (A/D) converter. The digital binary data is providedto MAC device 406.

MAC device 406 acts as an interface between the hardware and softwarecomponents of cable modem 210. In particular, MAC device 406 assigns anidentifier (i.e., a MAC address) to each component within a network,enabling software modules to uniquely identify the different componentsin the network. MAC device 406 is positioned between receive demodulator404 and transmit modulator 408.

Transmit modulator 408 converts the digital computer-network data intoradio-frequency signals for upstream transmission to cable head-end 110.Transmit modulator 408 typically includes an error-correction section, aQAM modulator, and a digital-to-analog (D/A) converter.

CPU 410 runs software (firmware) modules that are executed on cablemodem 210. For example, CPU 410 is configured to run modules that enablecable modem 210 to process IP-based television, voice, and data signals.In addition, CPU 410 is configured to run a trap-detection module of anembodiment of the present invention, as explained in greater detailbelow. CPU 410 may write data (such as, MIB variables) to memory 412(such as, for example, a flash memory) or may immediately send a message(e.g., an SNMP trap) to the cable head-end 110 (e.g., a NetworkOperation Center (NOC)). Based on the processing provided by the modulesrunning on CPU 410, IP-based television data can be provided totelevision 222, Internet data is provided to network interface 414, andvoice data is provided to telephone adaptor 416.

Network interface 414 allows cable modem 210 to communicate withcomputer 212 and computing device 218 over a computer network.Similarly, telephone adaptor 416 converts digital voice data processedby CPU 410 into a format used by a conventional telephone.

B. Example Software Components

In addition to processing IP-based television, voice, and data signals,cable modem 210 is configured to determine whether cable trap 128 isproperly installed between the location of customer 120 and cablehead-end 110 in accordance with an embodiment of the present invention.To perform these functions, cable modem 210 includes a plurality ofdifferent software (firmware) modules.

For example, FIG. 5 is a block diagram of example software (firmware)components of cable modem 210, including a trap-detection module 530 inaccordance with an embodiment of the present invention and one or moreadditional modules 532. Trap-detection module 530 and the one or moreadditional modules 532 are managed by a network management system 502.These modules have access to information stored in objects of MIB 540and translate this information to network management system 502 via adedicated data channel or set of data channels. For example,trap-detection module 530 has access to trap-detection object 542, andthe one or more additional modules 532 have access to one or moreadditional objects 544. The one or more additional modules 532 andtrap-detection module 530 are described in greater detail below.

The one or more additional modules 532 enable cable modem 210 to receiveand process IP-based television, voice, and/or data signals from cablehead-end 110. To properly transmit and receive IP-based television,voice, and/or data signals from cable head-end 110, cable modem 210establishes an appropriate connection with cable head-end 110.Establishing a connection may take several minutes and involves severalsteps. One of the first steps in establishing this connection is aranging process. During the ranging process, a distance between cablemodem 210 and cable head-end 110 is determined. This distance is used toensure that the signals traveling between cable modem 210 and cablehead-end 110 have sufficient power to be properly received at therespective locations. Even after a connection is properly established,cable head-end 110 periodically sends station-maintenance signals toensure that the connection between cable head-end 110 and cable modem210 is maintained. If cable modem 210 does not acknowledge and responseto a station-maintenance signal after a predetermined time period (e.g.,approximately 35 seconds), then one of the additional modules 532 causescable modem 210 to re-initiate the connection with cable head-end 110.Re-initiating the connection may take several minutes and may disruptvoice and/or data services. In other words, a customer's telephone callor Internet experience may be disrupted if the connection between cablehead-end 110 and cable modem 210 needs to be restarted from scratch(i.e., re-initialized).

Trap-detection module 530 is configured to determine whether one or morecable traps are properly installed between cable modem 210 and cablehead-end 110. In particular, trap-detection module 530 is configured totemporarily disrupt cable modem from listening to the dedicatedfrequency between cable modem 210 and cable head-end 110 and totemporarily listen to a particular cable-television frequency band(e.g., channel) to determine whether a television signal is present atthat frequency band.

The time period that trap-detection module 530 listens to thecable-television frequency is relatively short (e.g., approximately onesecond or less) for at least two reasons. First, listening to thecable-television frequency may disrupt voice and/or data signals beingtransmitted between cable modem 210 and cable head-end 110. Second,listening to the cable-television frequency may cause cable modem 210 tolose the connection with cable head-end 110, requiring the connection tobe restarted which may disrupt voice and/or data signals (as set forthabove). In embodiments of the present invention, trap-detection module530 performs steps to mitigate these potential disruptions to voice anddata services, as explained in greater detail below.

To detect a television signal at a particular frequency band (e.g.,channel) being tested, trap-detection module 530 may, for example,attempt to lock onto a QAM signal and/or may attempt to detect energyassociated with a carrier of the QAM signal. If, on the one hand, atelevision signal is present, this indicates that a cable trap is notproperly installed to block transmission of the television signal at theparticular frequency band (e.g., channel) being tested. If, on the otherhand, a television signal is not present, this indicates that a cabletrap is properly installed to block transmission of the televisionsignal at the particular frequency band (e.g., channel) being tested.

Trap-detection module 530 may store this information about the presenceor absence of a cable trap in a trap-detection object 542 of MIB 540.For example, trap-detection object 542 is configured to store a firstpiece of data (e.g., a logical 1) if trap-detection module 530determines that a television signal is present at a particular frequencyband, indicating that a cable trap is not properly installed to blockthat frequency band. If, on the other hand, trap-detection module 530determines that a television signal is not present at a particularfrequency band, then trap-detection object is configured to store asecond piece of data (e.g., a logical 0), indicating that a cable trapis properly installed to block that frequency band.

Trap-detection module 530 is configured to transmit the informationstored in trap-detection object 542 to network management system 502using a network protocol. For example, this information may betransmitted to network management system 502 via a SNMP trap.

Network management system 502 may enable cable modem 210 to detect thepresence or absence of a cable trap. For example, network managementsystem 502 may create trap-detection object 542 within a MIB 540 ofcable modem 210, and may install trap-detection module 530 on cablemodem 210.

V. Example Operation

FIG. 6 is a block diagram of an example method 600 for trap-presencevalidation in accordance with an embodiment of the present invention.Method 600 begins at a step 602 in which a trap-detection process isinitiated. In an embodiment, trap-detection module 530 enters thetrap-detection process in response to a polling command from networkmanagement system 502. In another embodiment, trap-detection module 530is programmed to periodically enter the trap-detection process. Forexample, trap-detection module 530 may be programmed to enter thetrap-detection process once a week, once a month, once a quarter, orsome other time period.

In a step 604, it is determined whether cable modem 210 is in a rangingprocess. If cable modem 210 is in a ranging process, the trap-detectionprocess is stalled until the ranging process completes as illustrated ina step 606. Alternatively, the trap-detection process could be stalledfor a predetermined time before resuming. In either case, stalling thetrap-detection process if a ranging process is in progress helpsmitigate against potential disruptions to the data and/or voice serviceswhich may be caused by listening to one or more cable-televisionfrequency bands (e.g., channels).

If, in step 604, it is determined that a ranging process is not inprogress, or after step 606, trap-detection module 530 determineswhether a telephone coupled to cable modem 210 is in use as indicated ina step 608. If a telephone is in use, then the trap-detection process isstalled until no telephone coupled to cable modem 210 is in use, asindicated in a step 610. Alternatively, the trap-detection process canbe stalled for a predetermined time period before resuming if it isdetermined in step 608 that a telephone is in use. In either case,stalling the trap-detection process if a telephone is in use helpsmitigate against potential disruptions to telephone services (e.g., acustomer's telephone conversation) which may be caused by listening toone or more cable-television frequency bands (e.g., channels).

If, in step 608, it is determined that a telephone is not in use, orafter step 610, trap-detection module 530 determines whether a dataconnection is in progress, as indicated in a step 612. If a dataconnection is in progress, then the trap-detection process is stalleduntil the data connection terminates, as indicated in a step 614.Alternatively, the trap-detection process can be stalled for apredetermined time period before resuming if it is determined in step612 that a data connection is in progress. In either case, stalling thetrap-detection process if a data connection is in progress helpsmitigate against potential disruptions to data services (e.g., acustomer's Internet experience) which may be caused by listening to oneor more cable-television frequency bands (e.g., channels).

If, in step 612, it is determined that a data connection is not inprogress, or after step 614, then trap-detection module 530 attempts todetect a video signal at a particular cable-television frequency band(e.g., channel) as indicated in a step 616. For digital cable signals,trap-detection module 530 may, for example, attempt to lock onto a QAMsignal. Trap-detection module 530 may also, for example, attempt todetect energy associated with a carrier of the QAM signal.

If in step 618 a video signal is detected, and if the signal is a QAMsignal, then the trap-detection process optionally determines whetherthe video signal originated from the cable head-end, as indicated in astep 620. For example, trap-detection module 530 may determine whether atarget PID is present to determine that the video signal originated fromthe cable head-end. Whether trap-detection module 530 confirms that thevideo signal originated from cable head-end 110 or not, trap-detectionobject 542 is updated to indicate that a cable trap is not properlyinstalled between cable modem 210 and cable head-end 110, as indicatedin a step 622. For example, trap-detection object 542 may store a firstpiece of data (e.g., a logical 1), indicating that a cable trap is notproperly installed to block the particular cable-television frequencyband (e.g., channel).

If, on the other hand, a video signal is not detected in step 618, thentrap-detection object 542 is updated to indicate that a cable trap isproperly installed between cable modem 210 and cable head-end 110, asindicated in a step 624. For example, trap-detection object 542 maystore a second piece of data (e.g., a logical 0), indicating that acable trap is properly installed to block the particularcable-television frequency band (e.g., channel).

Although the steps of the trap-detection process of the embodiment ofFIG. 6 are presented in a particular order, it is to be appreciated thatthis is for illustrative purposes only, and not limitation. For example,steps 604, 608, and 612 need not be performed in the order illustratedin FIG. 6, but may be performed in any permutation of orders as would beapparent to a person skilled in the relevant art(s). As a specificexample, the trap-detection process of the method illustrated in FIG. 6may be stalled any time it is determined that a ranging process is inprogress, a telephone is being used, and/or a data connection is inprogress.

VI. Conclusion

Described above are systems, apparatuses, and methods for automaticdetection of a cable trap and applications thereof. It is to beappreciated that the Detailed Description section, and not the Summaryand Abstract sections, is intended to be used to interpret the claims.The Summary and Abstract sections may set forth one or more but not allexemplary embodiments of the present invention as contemplated by theinventor(s), and thus, are not intended to limit the present inventionand the appended claims in any way.

1. A computer-implemented method for automatic trap-presence validation,comprising: (a) creating a trap-detection object in a managementinformation base of a cable modem, wherein the trap-detection object isconfigured to maintain data corresponding to whether a cable trap ispresent between a cable head-end and the cable modem; and (b) obtainingthe data from the trap-detection object to determine whether the cabletrap is present between the cable head-end and the cable modem.
 2. Thecomputer-implemented method of claim 1, further comprising: (c) sendinga command to a trap-detection module of the cable modem, wherein thecommand causes the trap-detection module to (i) determine whether avideo signal is present at a cable-television frequency and (ii) updatethe data maintained by the trap-detection object based on a presence orabsence of the video signal.
 3. The computer-implemented method of claim2, wherein step (c) comprises: (c1) sending a command to atrap-detection module of the cable modem, wherein the command causes thetrap-detection module to (i) determine whether aquadrature-amplitude-modulation (QAM) signal is present at acable-television frequency and (ii) update the data maintained by thetrap-detection object based on a presence or absence of the QAM signal.4. The computer-implemented method of claim 2, wherein step (c)comprises: (c1) sending a command to a trap-detection module of thecable modem, wherein the command causes the trap-detection module to (i)determine whether energy associated with a video signal is present at acable-television frequency and (ii) update the data maintained by thetrap-detection object based on a presence or absence of the energyassociated with the video signal.
 5. The computer-implemented method ofclaim 2, wherein step (b) comprises: (b1) obtaining a first piece ofdata maintained by the trap-detection object if the trap-detectionmodule determined the video signal was present, indicating an absence ofthe cable trap between the cable head-end and the cable modem; and (b2)obtaining a second piece of data maintained by the trap-detection objectif the trap-detection module determined the video signal was notpresent, indicating a presence of the cable trap between the cablehead-end and the cable modem.
 6. A method, implemented in a cable modem,for automatic trap-presence validation, comprising: (a) determiningwhether a video signal is present at a cable-television frequency; and(b) storing data as to whether the video signal is present, wherein afirst piece of data is stored if the video signal is present, indicatingabsence of a properly functioning cable trap between a cable head-endand the cable modem, and wherein a second piece of data is stored if thevideo signal is absent, indicating presence of a properly functioningcable trap between the cable head-end and the cable modem.
 7. The methodof claim 6, wherein (a) comprises: (a1) determining whether aquadrature-amplitude-modulation (QAM) signal is present at thecable-television frequency.
 8. The method of claim 6, wherein (a)comprises: (a1) determining whether energy associated with a videosignal is present at the cable-television frequency.
 9. The method ofclaim 6, wherein step (a) is executed in response to a request from thecable head-end.
 10. The method of claim 6, wherein step (a) is executedat one or more pre-programmed time intervals.
 11. The method of claim 6,further comprising: (c) sending the data as to whether the video signalis present to a network management system.
 12. A cable modem forautomatic trap-presence validation, comprising: a trap-detection moduleconfigured to determine whether a video signal is present at acable-television frequency; and a trap-detection object configured tostore data as to whether the video signal is present, wherein a firstpiece of data is stored if the video signal is present, indicatingabsence of a properly functioning cable trap between a cable head-endand the cable modem, and wherein a second piece of data is stored if thevideo signal is absent, indicating presence of a properly functioningcable trap between the cable head-end and the cable modem.
 13. The cablemodem of claim 12, wherein the trap-detection module is furtherconfigured to determine whether a quadrature-amplitude-modulation (QAM)signal is present at the cable-television frequency.
 14. The cable modemof claim 12, wherein the trap-detection module is further configured todetermine whether energy associated with a video signal is present atthe cable-television frequency.
 15. The cable modem of claim 12, whereinthe trap-detection module determines whether the video signal is presentin response to a request from the cable head-end.
 16. The cable modem ofclaim 12, wherein the trap-detection module determines whether the videosignal is present at one or more pre-programmed time intervals.
 17. Thecable modem of claim 12, wherein the trap-detection module is furtherconfigured to send the data stored by the trap-detection object to anetwork management system.
 18. A tangible computer-readable mediumhaving stored thereon computer-executable instructions that, if executedby a computing device, cause the computing device to perform a methodfor automatic trap-presence validation, the method comprising: (a)determining whether a video signal is present at a cable-televisionfrequency; and (b) storing data as to whether the video signal ispresent, wherein a first piece of data is stored if the video signal ispresent, indicating absence of a properly functioning cable trap betweena cable head-end and the cable modem, and wherein a second piece of datais stored if the video signal is absent, indicating presence of aproperly functioning cable trap between the cable head-end and the cablemodem.
 19. The tangible computer-readable medium of claim 18, wherein(a) comprises: (a1) determining whether aquadrature-amplitude-modulation (QAM) signal is present at thecable-television frequency.
 20. The tangible computer-readable medium ofclaim 18, wherein (a) comprises: (a1) determining whether energyassociated with a video signal is present at the cable-televisionfrequency.
 21. The tangible computer-readable medium of claim 18,wherein step (a) of the method is executed in response to a request fromthe cable head-end.
 22. The tangible computer-readable medium of claim18, wherein step (a) of the method is executed at one or morepre-programmed time intervals.
 23. The tangible computer-readable mediumof claim 18, wherein the method further comprises: (c) sending the dataas to whether the video signal is present to a network managementsystem.